Hitherto optical devices for the work with light and other electromagnetic radiation have been constructed out of solid materials. For example glass, plastics and other organic and inorganic transparent materials have been used to make lenses such as concave, convex, achromatic, composite lenses. The said material have also been employed to make prisms, polarizing prisms, polarizing sheets, optical retarders and the like. Occasionally entrained fluids given shape by the shaping of their transparent containers have been employed. Magnetic and electrostatic focusing devices have been used in electron, proton and ion microscopy. Such devices are using the magnetic or electrostatic field only, and in contrast to optical devices made of plasma are not constructed of a material body.
Metals in solid form or metals plated on substrates have been employed for concave, convex and complex, reflectors, mirrors and optical gratings. All of these optical devices operate well under ambient conditions up to elevated temperatures which the materials of their construction can take without encountering degradation or change in shape or composition. It is the object of this invention to provide optical devices which can operate at extremely high temperatures at which solid optical devices such as those made of plastics, metals, glass or refractory optical materials fail or cannot exist. The chosen material for the optical devices such as those mentioned above is plasma.